starting breast milk supply

A
So I called the lactation consultant support line when baby was about 5 days old and I was super engorged and asked about pumping. At that time they said to hold off and let baby eat (doc said feed every 2 hours) to avoid being a slave to the pump. 
I really want to start pumping to have a nice supply for when I go back to work and would like to get out of the house for a couple of hours. I'm now confused about pumping, how can I pump but still make sure there is enough for baby? 
I am going to start going to breastfeeding support classes once I'm able to drive again which isn't for 3 weeks unless I can get a ride!